Comparative Study on the Surface Dose of Some Bolus Materials

In order to investigate the possibility of using different materials as bolus in radiotherapy, five samples denoted by S2 - S6 were prepared and analyzed by comparison with one available commercial bolus denoted by S1. Sample S1 was a thermoplastic material from Qfix; S2 was a moldable silicon rubber RTV-530 from Prochima; S3 and S4 were obtained by adding micrometric particles of Al and Cu respectively at the same mass concentration of 5.5%; S5 was another moldable silicon rubber GSP400 from Prochima and S6 was a mixture of GSP400 and micrometric particles of Cu at the mass concentration of 5.5%. The measurements of normalized transmitted dose as a function of sample thickness were performed for all samples S1 - S6 at two values of electron beam energy 6 and 9 MeV produced by a linear accelerator VARIAN 2100SC. The results showed that the maximum of the normalized transmitted dose of manufactured samples S2 - S6 is registered at smaller sample thicknesses than for the analyzed commercial bolus sample S1. The smallest sample thickness corresponding to normalized maximum point dose is obtained for sample S2 RTV-530. Measurements performed for electron beam energy of 6 and 9 MeV have proven the possibility of using the manufactured samples as bolus in radiotherapy.